Glow-worm - Boiler Efficiency Rating

Compare new boilers and assess whether your current boiler needs to be replaced.

A boiler’s energy rating is an indicator of its efficiency when used within an average domestic household. It’s a great benchmark for comparing new boilers and can help you work out how much money you could save on energy bills if you replaced your current boiler with a more efficient model.

You can find out the energy efficiency of your boiler by checking its energy rating; you can do this now by selecting the make and model below.

How efficient is your boiler?

Select your boiler using the dropdown below to find out.

Glow-worm Boilers

ModelTypeFuelEfficiency
Glow-worm105-120105-120Non-CondensingGas65%
Glow-worm105-120B105-120BNon-CondensingGas65%
Glow-worm12hxiCondensingGas90.5%
Glow-worm15hxiCondensingGas90.5%
Glow-worm18hxiCondensingGas90.4%
Glow-worm18sxiCondensingGas90.4%
Glow-worm23cNon-CondensingGas79.9%
Glow-worm240Non-CondensingGas65%
Glow-worm246Non-CondensingGas65%
Glow-worm24ciNon-CondensingGas78.3%
Glow-worm24ci PlusNon-CondensingGas78.3%
Glow-worm24cxiCondensingGas90.3%
Glow-worm24hxiCondensingGas90.5%
Glow-worm30 ciNon-CondensingGas79.6%
Glow-worm30 siNon-CondensingGas79.7%
Glow-worm30ci PlusNon-CondensingGas79.6%
Glow-worm30cxiCondensingGas90.3%
Glow-worm30cxiCondensingLPG92.2%
Glow-worm30hxiCondensingGas90.6%
Glow-worm30hxiCondensingLPG92.2%
Glow-worm30sxiCondensingGas90.6%
Glow-worm30sxiCondensingLPG92.2%
Glow-worm35ciNon-CondensingGas78.6%
Glow-worm38cxiCondensingGas90.4%
Glow-worm38hxiCondensingGas90.8%
Glow-worm45Non-CondensingGas65%
Glow-worm45-6045-60Non-CondensingGas65%
Glow-worm45-60B45-60BNon-CondensingGas65%
Glow-worm45/2 BBUNon-CondensingGas68.4%
Glow-worm45/4 BBUNon-CondensingGas78.4%
Glow-worm45FNon-CondensingGas65%
Glow-worm45FRNon-CondensingGas65%
Glow-worm54/4 BBUNon-CondensingGas78.9%
Glow-worm56Non-CondensingGas65%
Glow-worm56/2 BBUNon-CondensingGas68.1%
Glow-worm56/3e BBUNon-CondensingGas78.5%
Glow-worm56/3pp BBUNon-CondensingGas74.5%
Glow-worm56FNon-CondensingGas65%
Glow-worm56FRNon-CondensingGas65%
Glow-worm65-8065-80Non-CondensingGas65%
Glow-worm65-80B65-80BNon-CondensingGas65%
Glow-worm85-10085-100Non-CondensingGas65%
Glow-worm85-100B85-100BNon-CondensingGas65%
Glow-wormBBU 45/4Chatsworth 4Non-CondensingGas79.5%
Glow-wormBBU 45/4Dovedale 4Non-CondensingGas79.5%
Glow-wormBBU 45/4Firelite 4Non-CondensingGas78.4%
Glow-wormBBU 45/4Contour 4Non-CondensingGas78.4%
Glow-wormBBU 45/4Heartbeat 4Non-CondensingGas78.4%
Glow-wormBBU 45/4Miami 4Non-CondensingGas78.4%
Glow-wormBBU 45/4Black Beauty 4Non-CondensingGas78.4%
Glow-wormBBU 54/4Chatsworth 4Non-CondensingGas79.4%
Glow-wormBBU 54/4Dovedale 4Non-CondensingGas79.4%
Glow-wormBBU 54/4Heartbeat 4Non-CondensingGas78.8%
Glow-wormBBU 54/4Black Beauty 4Non-CondensingGas78.8%
Glow-wormBBU 54/4Contour 4Non-CondensingGas78.8%
Glow-wormBBU 54/4Firelite 4Non-CondensingGas78.8%
Glow-wormBBU 54/4Miami 4Non-CondensingGas78.8%
Glow-wormBetacom 24CondensingGas86.7%
Glow-wormBetacom 24aCondensingGas90.0%
Glow-wormBetacom 24aCondensingLPG91.7%
Glow-wormBetacom 24cCondensingGas86.0%
Glow-wormBetacom 24cCondensingLPG87.0%
Glow-wormBetacom 28aCondensingGas90.1%
Glow-wormBetacom 28aCondensingLPG92.1%
Glow-wormBetacom 30CondensingGas87.1%
Glow-wormBetacom 30cCondensingGas86.4%
Glow-wormBetacom 30cCondensingLPG87.3%
Glow-wormBetacom2 24CondensingGas90%
Glow-wormBetacom2 24CondensingLPG91.7%
Glow-wormBetacom2 28CondensingGas89.8%
Glow-wormBetacom2 28CondensingLPG91.0%
Glow-wormCamelot240/6Non-CondensingGas65%
Glow-wormCapricorn246Non-CondensingGas65%
Glow-wormCapricorn240/6Non-CondensingGas65%
Glow-wormCompact 100 SystemANon-CondensingGas79.3%
Glow-wormCompact 100eNon-CondensingGas78.2%
Glow-wormCompact 100eANon-CondensingGas79.2%
Glow-wormCompact 100pNon-CondensingGas71.6%
Glow-wormCompact 60 SystemANon-CondensingGas79.5%
Glow-wormCompact 75eNon-CondensingGas77.5%
Glow-wormCompact 75pNon-CondensingGas72.1%
Glow-wormCompact 80eNon-CondensingGas77.8%
Glow-wormCompact 80eANon-CondensingGas79.5%
Glow-wormCompact 80pNon-CondensingGas72.2%
Glow-wormEasicom 24CondensingGas90.0%
Glow-wormEasicom 24CondensingLPG91.7%
Glow-wormEasicom 28CondensingGas89.8%
Glow-wormEasicom 28CondensingLPG91.0%
Glow-wormEconomy Plus75BNon-CondensingGas65%
Glow-wormEconomy Plus100fNon-CondensingGas72%
Glow-wormEconomy Plus 24BNon-CondensingGas75.1%
Glow-wormEconomy Plus 24FNon-CondensingGas77.2%
Glow-wormEconomy Plus 30BNon-CondensingGas71.3%
Glow-wormEconomy Plus 30CNon-CondensingGas72.4%
Glow-wormEconomy Plus 30FNon-CondensingGas75.7%
Glow-wormEconomy Plus 40BNon-CondensingGas71.9%
Glow-wormEconomy Plus 40CNon-CondensingGas71.9%
Glow-wormEconomy Plus 40FNon-CondensingGas77.0%
Glow-wormEconomy Plus 50BNon-CondensingGas73.1%
Glow-wormEconomy Plus 50CNon-CondensingGas72.4%
Glow-wormEconomy Plus 50FNon-CondensingGas76.3%
Glow-wormEconomy Plus 60BNon-CondensingGas75.4%
Glow-wormEconomy Plus 60CNon-CondensingGas73.8%
Glow-wormEconomy Plus 60FNon-CondensingGas75.8%
Glow-wormEconomy Plus 80FNon-CondensingGas77.6%
Glow-wormEnergysaver 30CondensingGas86.6%
Glow-wormEnergysaver 30eCondensingGas86.6%
Glow-wormEnergysaver 40CondensingGas86.7%
Glow-wormEnergysaver 40eCondensingGas86.7%
Glow-wormEnergysaver 40PCondensingLPG86.7%
Glow-wormEnergysaver 50CondensingGas86.8%
Glow-wormEnergysaver 50eCondensingGas86.8%
Glow-wormEnergysaver 50PCondensingLPG86.8%
Glow-wormEnergysaver 60CondensingGas86.9%
Glow-wormEnergysaver 60eCondensingGas86.9%
Glow-wormEnergysaver 60PCondensingLPG86.8%
Glow-wormEnergysaver 70CondensingGas87.9%
Glow-wormEnergysaver 80CondensingGas87.9%
Glow-wormEnergysaver 80PCondensingLPG88.0%
Glow-wormEnergysaver Combi 100CondensingGas90.4%
Glow-wormEnergysaver Combi 80CondensingGas90.6%
Glow-wormFlexicom 12hxCondensingGas90.7%
Glow-wormFlexicom 15hxCondensingGas90.5%
Glow-wormFlexicom 18hxCondensingGas90.4%
Glow-wormFlexicom 18sxCondensingGas90.3%
Glow-wormFlexicom 24cxCondensingGas90.3%
Glow-wormFlexicom 24hxCondensingGas90.3%
Glow-wormFlexicom 30cxCondensingGas90.0%
Glow-wormFlexicom 30hxCondensingGas90.0%
Glow-wormFlexicom 30sxCondensingGas90.1%
Glow-wormFlexicom 35cxCondensingGas90.2%
Glow-wormFlexicom 35hxCondensingGas90.3%
Glow-wormFuelsaver30-40BNon-CondensingGas65%
Glow-wormFuelsaver40-50bNon-CondensingGas65%
Glow-wormFuelsaver25-30Non-CondensingGas65%
Glow-wormFuelsaver30-40Non-CondensingGas65%
Glow-wormFuelsaver25-30BNon-CondensingGas65%
Glow-wormFuelsaver60-70bNon-CondensingGas65%
Glow-wormFuelsaver55-60bNon-CondensingGas65%
Glow-wormFuelsaver40-50Non-CondensingGas65%
Glow-wormFuelsaver40mk2Non-CondensingGas65%
Glow-wormFuelsaver40bmk2Non-CondensingGas65%
Glow-wormFuelsaver30mk2Non-CondensingGas65%
Glow-wormFuelsaver30bmk2Non-CondensingGas65%
Glow-wormFuelsaver60bmk2Non-CondensingGas65%
Glow-wormFuelsaver50bmk2Non-CondensingGas65%
Glow-wormFuelsaver60mk2Non-CondensingGas65%
Glow-wormFuelsaver75bmk2Non-CondensingGas65%
Glow-wormFuelsaver50mk2Non-CondensingGas65%
Glow-wormFuelsaver75mk2Non-CondensingGas65%
Glow-wormFuelsaver45fNon-CondensingGas68%
Glow-wormFuelsaver80fNon-CondensingGas68%
Glow-wormFuelsaver35fNon-CondensingGas68%
Glow-wormFuelsaver65fNon-CondensingGas68%
Glow-wormFuelsaver55fNon-CondensingGas68%
Glow-wormFuelsaver50brmk2Non-CondensingGas65%
Glow-wormFuelsaver60brmk2Non-CondensingGas65%
Glow-wormFuelsaver75brmk2Non-CondensingGas65%
Glow-wormFuelsaver40brmk2Non-CondensingGas65%
Glow-wormFuelsaver30brmk2Non-CondensingGas65%
Glow-wormFuelsaver100FNon-CondensingGas72%
Glow-wormFuelsaver Complheat 30Non-CondensingGas76.5%
Glow-wormFuelsaver Complheat 40Non-CondensingGas76.7%
Glow-wormFuelsaver Complheat 55Non-CondensingGas76.4%
Glow-wormFuelsaver Complheat 65Non-CondensingGas79.1%
Glow-wormFuelsaver Complheat 80Non-CondensingGas79.0%
Glow-wormFuelsaver Economy Plus24FNon-CondensingGas68%
Glow-wormFuelsaver Economy Plus40FNon-CondensingGas68%
Glow-wormFuelsaver Economy Plus80FNon-CondensingGas68%
Glow-wormFuelsaver Economy Plus50FNon-CondensingGas68%
Glow-wormFuelsaver Economy Plus60FNon-CondensingGas68%
Glow-wormFuelsaver Economy Plus30FNon-CondensingGas68%
Glow-wormFuelsaver Economy Plus60CNon-CondensingGas65%
Glow-wormFuelsaver Economy Plus30BNon-CondensingGas65%
Glow-wormFuelsaver Economy Plus40CNon-CondensingGas65%
Glow-wormFuelsaver Economy Plus24BNon-CondensingGas65%
Glow-wormFuelsaver Economy Plus50CNon-CondensingGas65%
Glow-wormFuelsaver Economy Plus40BNon-CondensingGas65%
Glow-wormFuelsaver Economy Plus60BNon-CondensingGas65%
Glow-wormGalaxie246Non-CondensingGas65%
Glow-wormGalaxie240/6Non-CondensingGas65%
Glow-wormHideaway60BLNon-CondensingGas65%
Glow-wormHideaway80LNon-CondensingGas65%
Glow-wormHideaway80BLNon-CondensingGas65%
Glow-wormHideaway60LNon-CondensingGas65%
Glow-wormHideaway90ofNon-CondensingGas65%
Glow-wormHideaway70ofNon-CondensingGas65%
Glow-wormHideaway 100Non-CondensingGas72.1%
Glow-wormHideaway 100BNon-CondensingGas73.0%
Glow-wormHideaway 100BFFNon-CondensingGas79.9%
Glow-wormHideaway 100CFFNon-CondensingGas79.9%
Glow-wormHideaway 115BFFNon-CondensingGas78.7%
Glow-wormHideaway 115CFFNon-CondensingGas78.7%
Glow-wormHideaway 120Non-CondensingGas73.0%
Glow-wormHideaway 120BNon-CondensingGas72.0%
Glow-wormHideaway 40Non-CondensingGas70.8%
Glow-wormHideaway 40BNon-CondensingGas71.5%
Glow-wormHideaway 40BFFNon-CondensingGas78.3%
Glow-wormHideaway 40CFFNon-CondensingGas78.3%
Glow-wormHideaway 50Non-CondensingGas71.0%
Glow-wormHideaway 50BNon-CondensingGas71.4%
Glow-wormHideaway 50BFFNon-CondensingGas78.2%
Glow-wormHideaway 50CFFNon-CondensingGas78.2%
Glow-wormHideaway 60Non-CondensingGas71.3%
Glow-wormHideaway 60BNon-CondensingGas71.7%
Glow-wormHideaway 60BFFNon-CondensingGas78.5%
Glow-wormHideaway 60CFFNon-CondensingGas78.5%
Glow-wormHideaway 70Non-CondensingGas71.8%
Glow-wormHideaway 70BNon-CondensingGas72.5%
Glow-wormHideaway 80Non-CondensingGas71.7%
Glow-wormHideaway 80BNon-CondensingGas72.6%
Glow-wormHideaway 80BFFNon-CondensingGas78.4%
Glow-wormHideaway 80CFFNon-CondensingGas78.4%
Glow-wormHideaway 90Non-CondensingGas71.7%
Glow-wormHideaway 90BNon-CondensingGas72.8%
Glow-wormInset BBU 40Non-CondensingGas75.5%
Glow-wormInset BBU 50Non-CondensingGas77.6%
Glow-wormMajorca346Non-CondensingGas65%
Glow-wormMajorca246Non-CondensingGas65%
Glow-wormMajorca240/6Non-CondensingGas65%
Glow-wormMajorca340/6autoNon-CondensingGas65%
Glow-wormMajorca340/6Non-CondensingGas65%
Glow-wormMicron 100FFNon-CondensingGas79.5%
Glow-wormMicron 120FFNon-CondensingGas78.1%
Glow-wormMicron 30 FFNon-CondensingGas78.3%
Glow-wormMicron 30FFNon-CondensingGas76.6%
Glow-wormMicron 40 FFNon-CondensingGas78.7%
Glow-wormMicron 40FFNon-CondensingGas77.3%
Glow-wormMicron 50FFNon-CondensingGas78.9%
Glow-wormMicron 60 FFNon-CondensingGas78.8%
Glow-wormMicron 60FFNon-CondensingGas77.2%
Glow-wormMicron 70 FFNon-CondensingGas78.3%
Glow-wormMicron 70FFNon-CondensingGas77.4%
Glow-wormMicron 80 FFNon-CondensingGas78.3%
Glow-wormMicron 80FFNon-CondensingGas77.2%
Glow-wormMicron100FFNon-CondensingGas77.5%
Glow-wormRoyale246Non-CondensingGas65%
Glow-wormRoyale240/6Non-CondensingGas65%
Glow-wormSaunier Duval SB30eANon-CondensingGas79.3%
Glow-wormSaunier Duval SD30eANon-CondensingGas79.2%
Glow-wormSpacesaver50bfNon-CondensingGas65%
Glow-wormSpacesaver38bfNon-CondensingGas65%
Glow-wormSpacesaver22-30bNon-CondensingGas65%
Glow-wormSpacesaver52Non-CondensingGas65%
Glow-wormSpacesaver75bfNon-CondensingGas65%
Glow-wormSpacesaver38Non-CondensingGas65%
Glow-wormSpacesaver45-60Non-CondensingGas65%
Glow-wormSpacesaver45-60bNon-CondensingGas65%
Glow-wormSpacesaver22-30fNon-CondensingGas65%
Glow-wormSpacesaver60fNon-CondensingGas68%
Glow-wormSpacesaver40fNon-CondensingGas68%
Glow-wormSpacesaver30bmk2Non-CondensingGas65%
Glow-wormSpacesaver30mk2Non-CondensingGas65%
Glow-wormSpacesaver30brmk2Non-CondensingGas65%
Glow-wormSpacesaver40bmk2Non-CondensingGas65%
Glow-wormSpacesaver80bmk2Non-CondensingGas65%
Glow-wormSpacesaver60mk2Non-CondensingGas65%
Glow-wormSpacesaver60bmk2Non-CondensingGas65%
Glow-wormSpacesaver50mk2Non-CondensingGas65%
Glow-wormSpacesaver50bmk2Non-CondensingGas65%
Glow-wormSpacesaver40mk2Non-CondensingGas65%
Glow-wormSpacesaver50fNon-CondensingGas68%
Glow-wormSpacesaver30-40fNon-CondensingGas68%
Glow-wormSpacesaver40-50rfNon-CondensingGas68%
Glow-wormSpacesaver20-30fNon-CondensingGas68%
Glow-wormSpacesaver20-30rfsNon-CondensingGas68%
Glow-wormSpacesaver20-30rfNon-CondensingGas68%
Glow-wormSpacesaver30-40rfNon-CondensingGas68%
Glow-wormSpacesaver50-60rfsNon-CondensingGas68%
Glow-wormSpacesaver40-50rfsNon-CondensingGas68%
Glow-wormSpacesaver30-40rfsNon-CondensingGas68%
Glow-wormSpacesaver50-60rfNon-CondensingGas68%
Glow-wormSpacesaver60brmk2Non-CondensingGas65%
Glow-wormSpacesaver80brmk2Non-CondensingGas65%
Glow-wormSpacesaver75Non-CondensingGas65%
Glow-wormSpacesaver50rmk2Non-CondensingGas65%
Glow-wormSpacesaver40rmk2Non-CondensingGas65%
Glow-wormSpacesaver60rmk2Non-CondensingGas65%
Glow-wormSpacesaver30rmk2Non-CondensingGas65%
Glow-wormSpacesaver40brmk2Non-CondensingGas65%
Glow-wormSpacesaver65-75fNon-CondensingGas68%
Glow-wormSpacesaver Complheat60Non-CondensingGas72%
Glow-wormSpacesaver Complheat70Non-CondensingGas72%
Glow-wormSpacesaver Kfb60Non-CondensingGas68%
Glow-wormSpacesaver Kfb70Non-CondensingGas68%
Glow-wormSpacesaver Kfb20Non-CondensingGas68%
Glow-wormSuburbanSuburbanNon-CondensingGas65%
Glow-wormSuper40bNon-CondensingGas65%
Glow-wormSuper40Non-CondensingGas65%
Glow-wormSuper30bNon-CondensingGas65%
Glow-wormSuper30Non-CondensingGas65%
Glow-wormSuper52bNon-CondensingGas65%
Glow-wormSuper52Non-CondensingGas65%
Glow-wormSwiftflow100Non-CondensingGas70%
Glow-wormSwiftflow75Non-CondensingGas70%
Glow-wormSwiftflow80Non-CondensingGas70%
Glow-wormSwiftflow 100Honeywell valveNon-CondensingGas70.7%
Glow-wormSwiftflow 100SIT valveNon-CondensingGas70.7%
Glow-wormSwiftflow 100eNon-CondensingGas76.6%
Glow-wormSwiftflow 120Non-CondensingGas73.1%
Glow-wormSwiftflow 125eNon-CondensingGas79.4%
Glow-wormSwiftflow 75Honeywell valveNon-CondensingGas71.4%
Glow-wormSwiftflow 75SIT valveNon-CondensingGas71.4%
Glow-wormSwiftflow 75eNon-CondensingGas76.5%
Glow-wormSwiftflow 80SIT valveNon-CondensingGas73.1%
Glow-wormSwiftflow 80Honeywell valveNon-CondensingGas73.1%
Glow-wormSwiftflow 80eNon-CondensingGas76.6%
Glow-wormUltimate80bfNon-CondensingGas65%
Glow-wormUltimate24hCondensingGas90.3%
Glow-wormUltimate35cCondensingGas89.9%
Glow-wormUltimate35cCondensingLPG91.5%
Glow-wormUltimate 100 FFNon-CondensingGas79.5%
Glow-wormUltimate 100FFNon-CondensingGas77.5%
Glow-wormUltimate 120FFNon-CondensingGas78.1%
Glow-wormUltimate 30BFNon-CondensingGas73.0%
Glow-wormUltimate 30cCondensingGas89.8%
Glow-wormUltimate 30cCondensingLPG91.5%
Glow-wormUltimate 30FFNon-CondensingGas79.7%
Glow-wormUltimate 30FF/LPNon-CondensingLPG78.0%
Glow-wormUltimate 40 FFNon-CondensingGas78.7%
Glow-wormUltimate 40BFNon-CondensingGas72.1%
Glow-wormUltimate 40FFNon-CondensingGas75.4%
Glow-wormUltimate 40FF/LPNon-CondensingLPG78.0%
Glow-wormUltimate 50 FFNon-CondensingGas78.8%
Glow-wormUltimate 50BFNon-CondensingGas73.1%
Glow-wormUltimate 50BF/LPNon-CondensingLPG74.8%
Glow-wormUltimate 50FFNon-CondensingGas76.0%
Glow-wormUltimate 50FF/LPNon-CondensingLPG80.1%
Glow-wormUltimate 60 FFNon-CondensingGas79.4%
Glow-wormUltimate 60BFNon-CondensingGas75.6%
Glow-wormUltimate 60FFNon-CondensingGas76.6%
Glow-wormUltimate 60FF/LPNon-CondensingLPG77.5%
Glow-wormUltimate 70 FFNon-CondensingGas79.3%
Glow-wormUltimate 70FFNon-CondensingGas77.1%
Glow-wormUltimate 80 FFNon-CondensingGas79.4%
Glow-wormUltimate 80FFNon-CondensingGas76.3%
Glow-wormUltimate 80FF/LPNon-CondensingLPG79.8%
Glow-wormUltracom 12hxiCondensingGas90.5%
Glow-wormUltracom 12hxiCondensingLPG91.6%
Glow-wormUltracom 15hxiCondensingGas90.5%
Glow-wormUltracom 15hxiCondensingLPG91.6%
Glow-wormUltracom 18hxiCondensingGas90.4%
Glow-wormUltracom 18hxiCondensingLPG91.5%
Glow-wormUltracom 18sxiCondensingGas90.4%
Glow-wormUltracom 18sxiCondensingLPG91.5%
Glow-wormUltracom 2 12sxiCondensingGas90.4%
Glow-wormUltracom 2 18sxiCondensingGas90.4%
Glow-wormUltracom 2 18sxiCondensingLPG92.1%
Glow-wormUltracom 2 24cxiCondensingGas90.3%
Glow-wormUltracom 2 24cxiCondensingLPG92.0%
Glow-wormUltracom 2 30cxiCondensingGas90.3%
Glow-wormUltracom 2 30cxiCondensingLPG92.4%
Glow-wormUltracom 2 30sxiCondensingGas90.5%
Glow-wormUltracom 2 30sxiCondensingLPG92.5%
Glow-wormUltracom 2 35 StoreCondensingGas90.6%
Glow-wormUltracom 2 35 StoreCondensingLPG92.4%
Glow-wormUltracom 2 35cxiCondensingGas90.4%
Glow-wormUltracom 2 35cxiCondensingLPG92.4%
Glow-wormUltracom 24cxCondensingGas90.3%
Glow-wormUltracom 24cxCondensingLPG91.4%
Glow-wormUltracom 24cxiCondensingGas90.3%
Glow-wormUltracom 24cxiCondensingLPG91.4%
Glow-wormUltracom 24hxiCondensingGas90.5%
Glow-wormUltracom 24hxiCondensingLPG91.9%
Glow-wormUltracom 30cxCondensingGas90.3%
Glow-wormUltracom 30cxCondensingLPG92.2%
Glow-wormUltracom 30cxiCondensingGas90.3%
Glow-wormUltracom 30cxiCondensingLPG92.2%
Glow-wormUltracom 30hxiCondensingGas90.6%
Glow-wormUltracom 30hxiCondensingLPG92.2%
Glow-wormUltracom 30sxiCondensingGas90.6%
Glow-wormUltracom 30sxiCondensingLPG92.2%
Glow-wormUltracom 38cxiCondensingGas90.4%
Glow-wormUltracom 38cxiCondensingLPG91.5%
Glow-wormUltracom 38hxiCondensingGas90.8%
Glow-wormUltracom 38hxiCondensingLPG92.4%
Glow-wormUltrapower 100 SXICondensingGas91.5%
Glow-wormUltrapower 100 SXICondensingLPG92.7%
Glow-wormUltrapower 170 SXICondensingGas91.5%
Glow-wormUltrapower 170 SXICondensingLPG92.7%
Glow-wormXtrafast 120Non-CondensingGas78.6%
Glow-wormXtrafast 96Non-CondensingGas79.4%
Glow-wormXtramaxANon-CondensingGas78.9%
Glow-wormXtramax HECondensingGas90.6%
Glow-wormXtramax HECondensingLPG92.0%

What are SEDBUK Efficiency Ratings?

From 1999 to 2015 boilers were ranked on the SEDBUK scale which stands for ‘Seasonal Efficiency of a Domestic Boiler in the UK’. While many still refer to SEDBUK as the standard energy rating scale, it was actually replaced in 2015 by the Energy related Products directive, or ErP. It’s directly related to the EU’s ambition to improve the energy efficiency of our homes and achieve the following targets by 2020:

  • 20% reduction in EU greenhouse gas emissions (compared to 1990 levels)
  • 20% improvement in overall energy efficiency (across the EU)
  • 20% more energy produced from renewable resources such as solar or biomass.

Under the current ErP standards, boiler manufacturers are required to label their products with a rating from A++ to G, with G being the least efficient a boiler can be. In September 2019, efficiency grade A+++ will be added and the least efficient class, G, will be removed as an option, removing these products from the market as a result.

How Much Money Could I Save with a More Efficient Boiler

To understand how a new boiler could save you money, you need to consider the energy that an inefficient boiler is wasting. For example, if a boiler is only 70% efficient, for every £1 you spend on heating your home, 30p is being wasted on lost energy. If your new boiler can reach efficiency of 90%, that is just 10p lost of every £1. So that’s a saving of 20p in every £1 which really adds up over time.

The financial savings you could make by replacing your boiler with a more efficient model can be significant, but will vary depending on the size of your home, the fuel used by the boiler and the inefficiency of your existing boiler.

According to the Energy Saving Trust: “Replacing an old gas boiler with a programmer and room thermostat, with a new A-rated condensing boiler with a programmer, room thermostat and thermostatic radiator controls (TRVs) could save you:

Old Boiler ErP RatingEfficiencyDetached houseSemi-detached houseMid-terrace house
D78 – 82%£170£110£100
E74 – 78%£190£125£105
F70-74%£220£145£125
G<70%£320£210£180

Figures taken from the latest research by the Energy Saving Trust. Based on fuel prices as of April 2017.

For new boiler installations visit Boiler Guide to request quotes from independent local and regional heating engineers.